Radio tube socket unit



Sept. 11, 1934. s. H. EVANS RADIO TUBE SOCKET UNIT Filed NOV. 25, 1933 jwuc ntoz 5 E A NS Patented Sept. 11, 1934 UNITED STATES RADIO TUBE SOCKET UNIT Samuel H. Evans, Cincinnati, Ohio Application November 25,

10 Claims.

The invention forming the subject matter of this application relates to a mechanical assembly of certain control units commonly connected permanently to the terminal lugs of tube sockets used in radio sets.

In the present methods of assembling radio sets, a great deal of manual labor is involved in placing and soldering wires connecting the tube socket lugs with the various control elements, usually located in convenient positions underneath the chassis. In some sets this wiring, unshielded, is formed up on small cables; on other sets, it is strung so that it resembles a spiders web. In these sets, every bit of unshielded wire acts as a pick-up, especially for powerful local stations; thereby materially counteracting the effect of selective tuning between the tube circuits.

One of the objects of the present invention is, 20 therefore, to eliminate the said unshielded mass of wiring along with the objectionable inductive effects between the tube circuits.

Another object of the invention involves the assembling and arrangement of these tube circuits to increase selectivity by eliminating pick-up after connection to aerial.

A further object of the invention relates to material simplification of the chassis assembly,' by rendering the tube control units readily accessible for testing, repair or replacement.

Other objects of the invention, will become apparent as the detailed description thereof proceeds.

In the drawing:

Figure 1 is a fragmentary diagram illustrating a partial radio circuit of a screen grid tube with the control elements in electrical relation in the said circuit.

Figure 2 is a perspective view of the complete assembly;

Figure 3 is a central vertical section through the assembly; and

Figure 4 is a perspective view of a tube socket shield forming part of this invention.

The idea underlying this invention refers solely to the mechanical arrangement of those elements of capacity, inductance and resistance required to establish correct functional values of the tube elements. Taking the tube plate circuit as an example; if it is required to lower the B-battery potential, a resistance is used for this purpose. If it is not necessary to lower this potential, it is desirable to use a radio frequency choke coil. In either case, a condenser is usually placed to isolate further the R. F. of the plate circuit. So

1933, Serial No. 699,796

far as the plate circuit is concerned, the assembly includes, therefore, a condenser, and a resistance or a R. F. choke coil.

Similarly, the screen grid circuit requires a resistance in the line to the B-battery, and a 60 condenser to ground; while the cathode circuit includes a condenser and a resistance, both grounded. We have, therefore, a total of three condensers, and three resistances, or two resistances and one choke coil, forming the control 5 elements required for each tube. It is the purpose of this invention, to connect these six elements permanently to the appropriate lugs of a tube socket, so as to form with that socket a mechanical unit which may be bodily assembled on or detached from the chassis of a radio set. For convenience of description, this assembly may be referred to hereinafter as a tube-socket unit. The R. F. transformer shown in Figure 1 is not included as part of this tube-socket-unit.

In Figure l, the plate P is illustrated as connected through a condenser C to ground, and through resistance or choke R to the battery B. The screen grid S. G. is connected through condenser C1 to ground; and through resistance R1 to the battery B. The cathode K is likewise connected through the condenser C2 and resistance R2 to ground. These six elements constitute the fixed controls for the tube T; and are permanently connected to and supported by the tube socket S. (See Figures 2 and 3.)

The tube socket S, of the common wafer type, comprises the fiber base plate 1, having the usual socket lugs secured to the lower face thereof in proper relation to the holes 9 through which the prongs at the base of the tube S are adapted to project. The base plate 1 is seated on an assembly ring 11, which at diametrically opposite points is provided with apertures 12 and 13 adapted to register with apertures 14 and 15 formed in the base plate 1.

The assembly ring 11 has an annular flange 18 projecting from its lower face. This flange fits snugly in an aperture 19 formed in the chassis base 20 and projects sufficiently below the lower face of base 20 to receive and support the tube socket shield 21 which enclose the six condenser and resistance elements of the unit. It will be apparent that the ring 11 and the plate 1 can be secured to the chassis by screws, or other suitable fastening devices, passing through the registering apertures 12, 13, 14 and 15.

Preferably, the cylindrical condensers, resistances and choke coils are mounted at right angles to the base plate of the socket and parallel to the vertical axis of the tube socket. As shown in Fig 'ure 3, the control condenser C and resistance R are electrically connected, as by soldering, to the plate terminal lug 22 of the tube socket; the control condenser C1 and resistance R1 are connected to the screen grid terminal lug 23; and the condenser C2 and resistance R2 are connected to the cathode lug 24 of said socket. One terminal of each pair of control elements is soldered directly to the corresponding tube socket lug. Thus, the screen grid socket lug has one terminal of a resistance and a condenser soldered to it.

The free terminals of the screen grid and plate resistances are to be soldered to a common battery wire terminated at a convenient location on the unit for soldering to the main B-battery lead of the set, after. the tube socket unit has been mounted on the chassis. The free terminals of the condensers may have a common ground, either through the chassis plate, or through a lug conveniently mounted in the unit for connection to the main ground lead of the set, after the unit has been mounted in the chassis. The free terminal of the cathode lead may be wired to the common ground of the tube socket unit.

Thus when the control condensers and resistances have been mounted on the tube socket, and proper connections made, the only connections remaining to be made after the tube socket-unit is fixed to the chassis, are the filament and 3- battery leads to the unit, and the connections to the preceding and succeeding tube circuits..

The resistances, condensers and choke coils are made up, commercially, in such a variety of forms that, obviously, the mechanical applications of the tube-socket-unit would be likewise varied-dependent mainly on the cost of the unit. For this reason, no attempt is made herein to disclose anything but the general idea of combining the various tube control elements with a tube socket to form a unit which may be handled bodily.

When a radio set is designed, laboratory tests are made to establish permanently the values of these control elements for each tube in that particular type of set. This makes it possible to determine that when the control elements, having the necessary fixed values, have been mounted on a tube socket to form a tube-socket-unit for each tube in a given set, there will beno necessity to change any of such control elements.

The tube socket shield is divided by partitions 24, 25, 26 and 27 forming chambers in which the several pairs of control elements are located and shielded from each other when the socket shield is secured to the flange 18 of the assembly ring 11. The tube socket shield may be secured to the flange 18, either by friction, or by any suitable form of bayonet joint.

The shielded tube-socket construction just described, renders the tube control elements readily accessible for repair or replacement. By complete shielding of the tube control elements, a very sensitive set is made possible, when the tubesocket-unit method of assembly is used and properly shieldedwith the condensers and coils of tuned circuits also shielded, full advantage is had of the selective tuning effect of each tube, since there is then no pick-up anywhere in the circuits following aerial connection. A further advantage of this method of socket assembly is that, if it be desired to substitute a later type tube in a set, the

substitution of a corresponding tube-socket-unit 1. A tube socket unit comprising an assembly ring, a tube socket secured to said ring, and condensers and resistances in pairs electrically connected to and supported by appropriate lugs of said socket, and means for shielding each of said pairs.

2. A support, a radio tube socket having plate and cathode lugs and secured to said support, and plate and cathode control elements secured to and suspended from said lugs.

3. The combination set forth in claim 2 with means for shielding each of said elements.

4. A support, a radio tube socket having plate and cathode lugs and secured to said support, a condenser and a resistance secured to and supported by the plate socket lug, and a condenser and a resistance secured to and supported by the cathode socket lug.

5. A support, a radio tube socket having plate and cathode lugs and secured to said support, a condenser and a resistance secured to and supported by the plate socket lug, and a condenser and a resistance secured to and supported by the cathode socket lug, and means for separately shielding the condenser and resistance secured to the plate and cathode lugs.

6. A tube socket unit comprising an assembly ring, a tube socket secured to said ring, and tube control elements electrically connected to and suspended by terminal contact lugs of said socket.

7. A tube socket unit comprising an assembly ring, a tube socket secured to said ring, and tube control elements electrically connected to and suspended from terminal contact lugs of said socket, and a shield enclosing said elements.

8. A tube socket unit comprising an assembly ring, a tube socket secured to said ring, and condensers and resistances in pairs electrically connected to and suspended from appropriate lugs of said socket, and a shield enclosing said pairs.

9. A support, a radio tube socket adapted to receive a screen grid tube and secured to said support, a condenser and a resistance electrically connected to and suspended from the screen grid lug of said socket, a condenser and a resistance electrically connected to and suspended from the plate lug of said socket, and a condenser and a resistance secured to and suspended from the cathode lug of said socket.

10. A support, a radio tube socket adapted to.

receive a screen grid tube and secured to said support, a condenser and a resistance electrically connected and suspended from the' screen grid lug of said socket, a condenser and a resistance electrically connected to and suspended from the plate lug of said socket, and a condenser and a resistance secured to and suspended from the cathode lug of said socket, and means for shielding the condenser and resistance of each lug from the condensers and resistances of the other lugs.

SAMUEL H. EVANS. 

